In general, various cooling apparatuses are applied to vehicles in order to cool heat generated within an engine. Typical cooling apparatuses include an intercooler, an EGR cooler, and an oil cooler.
The intercooler is a heat exchanger for cooling air when a temperature of air is increased due to compression of a turbocharger. The intercooler is classified into an air cooled type of intercooler and a water cooled type of intercooler, and in order to enhance fuel efficiency in consideration of cooling performance and turbo lag, the water cooled type of intercooler, rather than the air cooled type of intercooler, is applied.
The EGR cooler is an apparatus for cooling a recirculated exhaust gas using a coolant or a cooling wind of an engine. EGR is a method of recirculating a partial amount of an exhaust gas to an intake so that the exhaust gas flows again to an engine combustion chamber. According to this method, a partial amount of oxygen introduced to the engine is replaced with an inert gas, reducing a generation rate of NOx, and a combustion temperature is lowered to restrain generation of NOx. Here, since EGR supplies a high temperature exhaust gas to the intake, a component may be damaged, and thus, in order to cool the exhaust gas, an EGR cooler is additionally provided.
An oil cooler is an apparatus for cooling charged oil to allow a component such as an engine or a transmission to smoothly operate. When oil is heated, viscosity thereof weakens, and the oil having weakened viscosity cannot properly perform a lubricating function. In order to solve this problem, the oil cooler cools oil.
The related art intercooler, EGR cooler, and oil cooler are independently formed and installed in different positions according to purposes of each cooling apparatus. Here, when the cooling apparatuses are independently installed, a space for disposing other components of the engine is reduced and a cooling circuit is complicated. Also, since heat is not transmitted between the cooling apparatuses, it is difficult to effectively control the cooling system.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.